Manually-controlled circuit

ABSTRACT

An electronic chassis is provided at its forward edge with a pivoted foot pedal overlying the chassis. The pedal is journaled between projecting sidewalls of the chassis, and through linkages, actuates a control mounted to the chassis. At the rear of the chassis is an upright housing in which relatively large heat-generating components cause a rising column of air which, through venturi action, creates a draft in a portion of the assembly located above the heat-generating components, the latter draft serving to cool other components mounted in the upper portion of the chassis.

United States Patent [72] inventor Morris L. Tucci Van Nuys, Calif.

[21] Appl. No. 451,446

[22] Filed Apr. 28, 1965 [45] Patented Feb. 2, 1971 [73] Assignee Warwick Electronics Inc.

Chicago, 111. a corporation of Delaware [54] MANUALLY-CONTROLLED CIRCUIT 4 Claims, 8 Drawing Figs.

[52] 11.5. Cl 84/1.27, 84/1.24, 74/478, 74/512, 317/100 [51] 1nt.Cl GOSg l/14, GOSh 1/02 [50] Field oi Search 84/1 .24,

1.26,1.09,1.27;3l 7/101,100,101D,101DH; 74/560,561,512, 478

[56] References Cited UNITED STATES PATENTS 2,986,953 6/1961 Dearmond et a1. 84/1.27

3,217,081 11/1965 Nakada 84/1.27 3,274,449 9/1966 Pioch 317/101 2,5 34,939 12/ 1 950 Alkire 1 74/560 2,863,329 12/1958 Montgomery. 74/560 3,247,896 4/1966 Chu et al. 317/100 3,253,646 5/1966 Koltuniak et al. 317/100 Primary Examiner-Donald D. Forrer Assistant ExaminerB. P. Davis Att0rney-"Warren T. Jessup ABSTRACT: An electronic chassis is provided at its forward edge with a pivoted foot pedal overlying the chassis. The pedal is joumaled between projecting sidewalls of the chassis, and through linkages, actuates a control mounted to the chassis. At the rear of the chassis is an upright housing in which relatively large heat-generating components cause a rising column of air which, through venturi action, creates a draft in a portion of the assembly located above the heat-generating components, the latter draft serving to cool other componen mounted in the upper portion of the chassis.

PATENTEUFEB 21971 3.560.629

SHEET 1 'UF' 2 INVENTOR.

MOPQ/S I. 1 160 @MQ' aw. 56 BY MANUALLY-CONTROLLED CIRCUIT This invention relates to electromechanical devices, but relates specifically to an expression pedal structure for an electric organ, containing subcircuitry and a foot pedal to control the output from said subcireuitry into the electric organ system.

It is an object of this invention to provide a combination of a structure which has the dual function of housing subcircuitry of a greater organization, and the mechanical structure a required to control the output of said subcircuitry.

For example, it is the object of the preferred construction to provide a self-contained combination of an amplifier circuit, and a foot controlled potentiometer to provide output volume control of the amplifier, known in organ parlance as expression control.

Another object of this invention is to provide a compact self-contained unit combination wherein the manual pedal is carried by the amplifier housing. Manual is intended in its broadest concept of being manipulated by the operator.

Yet another object of this invention is to provide a unitary, combination amplifier and foot control, within an organ cabinet, wherein one end of the amplifier carries the foot control projecting from the front cabinet wall, and the amplifier presents facilities thereof to the back cabinet wall.

It is a further object of this invention to provide an improved expression pedal control for an electric organ wherein the expression pedal and its associated circuitry is provided in a package unit which may be installed or removed from the organ as an operative unit for a separate manufacture, and for separate maintenance and inspection.

For a full understanding of the invention, a detailed description of the preferred embodiment of the MANUALLY-CON- TROLLED CIRCUIT will now be given in conjunction with the accompanying drawings and the features forming the invention will then be specifically pointed out in the appended claims:

FIG. 1 is a plan view of a chassis and foot pedal control combination;

FIG. 2 is a side elevation of the FIG. 1 construction at a first extreme of physical adjustment:

FIG. 3 is the side elevation of FIG. 2 in a second extreme of adjustment;

FIG. 4 is a section taken through line 4-4'of FIG. 3;

FIG. 5 is the front view of an electric organ showing the structure in a typical environment;

FIG. 6 is a side elevation of an alternative embodiment;

FIG. 7 is a plan view of the structure shown in FIG. 6; and

FIG. 8 is a section detail through the top vertical housing of FIG. 6.

The drawings illustrate an expression pedal 10 as employed in the illustrative environment of an electric organ 12 (See FIG. 5). The detail of construction is illustrated in the balance of the FIGS.

In FIG. 1 a housing 14 provides a chassis top 16 which is mountable above a supporting surface in order to carry electric and electronic devices and connecting circuits and wiring suitable to serve an integrated function or portion of a larger system. For example, the power amplifier and associated circuitry of the organ is preferably provided in one serviceable assembly, such as that shown.

The illustrated embodiments employ a sloping front wall 18 which projects forwardly and downwardly from the plane or level of the top 16. This is also known as a cascading front wall because in the preferred embodiment it has somewhat the form of a water cascade.

In the most common construction, the chassis will be supported at an elevation by means of sidewalls 20, as shown in FIGS. 2 and 4. Thus housing 14, in a preferred embodiment, is more of an enclosed housing than an open supported chassis top.

The sidewalls are usually rectangular and have front edge areas'22 and rear edge areas 24. The preferred embodiment is constructed from a single piece of sheet material, and therefore, in order to provide the cascading front wall 18, a tab is cut from the sheet by means of longitudinal slots which end at position 26 along the dividing area between the top and sidewalls. Thus, the chassis top 16 may be said to begin in the area of the rear edge 24 and the proceed forwardly to the intermediate area 26, whereupon the top then cascades as the front wall 18.

The wall 18 is secured between the sidewalls 20 and thus provides stability for these walls.

A novel feature of the present invention is the provision of a pedal 28 which is mounted by pivot 30 between the sidewalls 20 beyond and above the cascading front wall 18. Thus, the housing provides not only a chassis mounting for the electrical gear, but also a mechanical mounting for a pivotal foot control pedal.

A swingable circuit board 32 is attached to the front wall 18 midway between its terrninal ends, and is secured on the sidewalls 20 to provide additional mounting space for electrical means.

No effort is made throughout the present disclosure to illustrate specific circuits or equipment and only suggestive sketches are included to indicate the possible locations of such and wiring. However, it is intended that the electromechanical relationship be established through the instrumentality of an electronic device which may be mechanically adjusted to effect theoutput of the subcircuit contained within the housing 14.

To this end, a potentiometer 34 is shown as one possible electric device which may be mechanically controlled. Other adjustable devices, such as multiple switches or rheostats, may be employed.

In order to provide for the mechanical attachments of the electric control device 34, a shaft 36 is extended through one of the sidewalls 20 by means of a suitable bearing, and projects to the exterior of the housing 14. A lever arm 38 is attached to the shaft and is secured in a proper adjustment position by means of a set screw 39.

Link 40 interconnects between the toe-supporting area of pedal 28 and the end of the lever arm 38. The link 40 is attached to the pedal by means of a pivot 42.

Modern organ construction faces the dual and contradictory trends of smaller and more graceful cabinets but more bulk of electronic gear and apparatus to enhance the usefulness and desirability of the organ. Therefore, the present invention has as one of its objects the placement of all of the amplifier circuitry, and its foot control, in a minimum of space and well located for ease of construction and service.

It is a further intent of this invention to provide the compact structure in its most useful form. Hence, it is the intention to provide the housing of the amplifier such that it extends through the cabinet from front to back, presenting manual control apparatus on the front end and facilities such as attachments and adjustments available on the rear. Note that the housing 14 is provided with a receptacle 35 for reception of a lead from a remote speaker cabinet. Back wall 13 is slotted to receive such a plug device.

Furthermore, it is intended that the entire assembly be quickly removable for service. Hence, one of the service features of the invention is shown best in FIG. 3. It is desirable that the service manhave access to all of the components needing service with a minimum of dismantling operation. To make the amplifier as compact as possible, however, the components are of necessity placed closely within the housing. This invention provides a novel solution to accessibility by the provision of the swingable circuit board 32 shown in FIG. 3. This circuit board 32 is attached to the front wall 18, and is pivotally mounted on the sidewall 20 by means of rivets 33. Circuit board 32 is constructed in the typical manner of printed circuits, having printed or etched conductors on one side, and openings for the terminals of electronic components extending through the board and attached into the circuit. It is often necessary to remove such component and' thus a soldering iron is touched to the circuit attachment and a component is released and a new one soldered in place. According to this invention, the circuit board 32 may be released from the front wall and swung downwardly to make both sides of the board accessible. This fact is suggested by the dotted line illustration of board 32 in a partially opened position.

The housing provides limit stops for movement of the pedal, in order to establish the proper adjustment of the device 34. Pads 44 and 45 are placed to cushion the contact of the pedal as it reaches such limit of movement. The line 40 and the length of the pivot arm 38 are then constructed to cause the desired rotational movement of shaft 36 within these mechanical limits.

Some organs have need for a single amplifier, and others have two speaker systems requiring two amplifier systems. Normally a potentiometer controlling an rotates through the major portion of a complete 360 range. However, it is possible to build a potentiometer of lesser movement, and the potentiometer 34 is designed to operate through a relatively small rotation, as shown by the difference in position of FIGS. 2 and 3.

However, it is more difficult to design and coordinate a double potentiometer in a gang in such small amount of rotation, and therefore in some instances it is necessary to devise linkage which will create a greater rotation than the linkage shown in FIG. 2.

In FIG. 6, an alternative construction is illustrated in the fonn of a rack 47 and pinion 48. Pinion 48 is secured by a set screw to the shaft 36 and the rack 47 is held in contact with the pinion by means of a bar retainer 49. .This produces a rotation over a major portion of a 360 cycle.

Whenever an organ requires a dual amplification system, this invention may be modified to provide the dual amplification without using any greater width than that illustrated in FIG. 1. It is desirable to keep this minimum width relationship in order to provide greater floor space available within the cabinet housing for other apparatus.

Therefore, as a further utilization of the combination, a vertical-housing 51 is shown secured at the rear portion of the housing 14 in FIG. 6. This housing 51 is illustrated as having a front wall 52 and opposed sidewalls 53. A novel and useful service feature is then provided by means of a swing board 55 pivotally mounted by pivots 57 between the sidewalls 53, in the manner and for the purpose described with respect to the board 32. Thus, the board 55 may be pivoted into the position shown in FIG. 6 during operative useof the combination and may be swung to the position shown in FIG. 8 for accessibility to the underside of the board for service and testing.

The swing board 55 is constructed with a top plate 58 and a printed circuit board 60. The board 60 is carried by the plate 58 by means of spacers 61. Thus, there is a continuous space 63 from the bottom through to the top of the swing board which extends upwardly at a sloping angle as shown best in FIG. 6.

The components which are placed on the board portion 60 require a removal of excess heat to prevent early deterioration. It has been discovered that by placing a power transformer of the amplifier on the top surface 16a within the wall 51, a chimney effect is created by the heat rising from the power pack and the air will flow through space 65 between the pivot 57 and the wall 52.

Such movement of air creates a venturi effect on the space 63 and causes air to flow between the plate 58 and the board portion 60. Thus, heat is extracted from the elements. If the element is placed on the bottom side of the board portion 60, the heat from the element will be extracted through its terminal lead. Therefore, the element which produces the greatest amount of heat in a transistorized device, the power pack, is deliberately employed to assist in cooling those elements of the circuit which are most susceptible to heat degeneration.

Thus, the foot pedal control circuit system illustrated in the embodiment of the drawings, is a self-contained elec tromechanical combination which provides a unique and'serherein in what is conceived to be the most practical and preferred embodiments, it is recognized that departures may be made therefrom within the scope of the invention which is therefore not to be limited to the details disclosed herein but is to be afforded the full scope of the invention as hereinafter claimed.

1 claim:

l. A foot pedal controlled circuit system, including in combination:

a housing having a top wall and opposed lateral sidewalls, said sidewalls having a front edge and rear edgejsai'd housing being a unitary structure having a pair of longitudinal slots in said sidewall respectively adjacent said sidewalls to produce a tab extension of said top wall, said tab extension extending forwardly and downwardly to a position between said sidewalls below the upper edges of said sidewalls;

a foot pedal having a heel support portion, a toe support portion, and an intermediate portion, said pedal having a width dimensioned to fit between said sidewalls,'pivot means at said from front edges of said sidewalls for supporting said intermediate portion of the pedal'with said toe portion of the pedal extending over said top wall;

control circuit means carried by said housing, said control circuit means including a physically-adjustable member;

linkage means interconnecting said pedal and adjustable member for control of said circuit means by said pedal;

said housing defining a first upright passageway and a second passageway, said second passageway having an exit in communication with the upper portion of said first passageway; and

a first heat-producing electronic component mounted in said first passageway below said upper portion thereof, and a second electronic component mounted in heat-dissipating relationship with said second passageway; so that upward draft created at said exit of said second passageway creates a secondary draft through said second passageway thereby to cool said second compartment.

2. The combination defined in claim 1, in which said first passageway is restricted at its upper portion thereby to accelerate the upward draft created by said first component, and the exit of said second passageway is directed generally upwardly contiguous to and in communication with the restricted portion of said first passageway.

3. The combination defined in claim 1, in which said first passageway is generally rectangular in cross section, the upper portion of said first passageway being narrowed obliquely by a diagonally positioned first wall forming a restricted mouth at said upper portion of said first passageway, said second passageway being formed by another diagonally positioned wall substantially paralleling and spaced from said first wall and being open at its lower and upper ends; so as to permit passage of said secondary draft therethrough, said exit of said second passageway being contiguous to the mouth of said first passageway.

4. The combination defined in claim 3, in which said first wall and said second-mentioned diagonally positioned wall form a unitary structure and define between them said second passageway, said structure being secured to the remaining portion of said housing for pivotal movement about a horizontal axis passing through the upper portion of said unitary structure, so that said unitary structure constitutes an upper sloping wall for said first passageway which may be pivoted upwardly to expose said first wall and thereby give access for servicing said second component. 

1. A foot pedal controlled circuit system, including in combination: a housing having a top wall and opposed lateral sidewalls, said sidewalls having a front edge and rear edge; said housing being a unitary structure having a pair of longitudinal slots in said sidewall respectively adjacent said sidewalls to produce a tab extension of said top wall, said tab extension extending forwardly and downwardly to a position between said sidewalls below the upper edges of said sidewalls; a foot pedal having a heel support portion, a toe support portion, and an intermediate portion, said pedal having a width dimensioned to fit between said sidewalls, pivot means at said from front edges of said sidewalls for supporting said intermediate portion of the pedal with said toe portion of the pedal extending over said top wall; control circuit means carried by said housing, said control circuit means including a physically-adjustable member; linkage means interconnecting said pedal and adjustable member for control of said circuit means by said pedal; said housing defining a first upright passageway and a second passageway, said second passageway having an exit in communication with the upper portion of said first passageway; and a first heat-producing electronic component mounted in said first passageway below said upper portion thereof, and a second electronic component mounted in heat-dissipating relationship with said second passageway; so that upward draft created at said exit of said second passageway creates a secondary draft through said second passageway thereby to cool said second compartment.
 2. The combination defined in claim 1, in which said first passageway is restricted at its upper portion thereby to accelerate the upward draft created by said first component, and the exit of said second passageway is directed generally upwardly contiguous to and in communication with the restricted portion of said first passageway.
 3. The combination defined in claim 1, in which said first passageway is generally rectangular in cross section, the upper portion of said first passageway being narrowed obliquely by a diagonally positioned first wall forming a restricted mouth at said upper portion of said first passageway, said second passageway being formed by another diagonally positioned wall substantially paralleling and spaced from said first wall and being open at its lower and upper ends; so as to permit passage of said secondary draft therethrough, said exit of said second passageway being contiguous to the mouth of said first passageway.
 4. The combination defined in claim 3, in which said first wall and said second-mentioned diagonally positioned wall form a unitary structure and define between them said second passageway, said structure being secured to the remaining portion of said housing for pivotal movement about a horizontal axis passing through the upper portion of said unitary structure, so that said unitary structure constitutes an upper sloping wall for said first passageway which may be pivoted upwardly to expose said first wall and thereby give access for servicing said second component. 